Wire-tensioning apparatus for drum filters



April 28, 1953 J. E. ROGERS WIRE-TENSIONING APPARATUS FOR DRUM FILTERS Filed April 28, 1950 mmvrox.

ATTO E) Patented Apr. 28, 1953 WIRE-TENSIONING APPARATUS FOR DRUM FILTERS.

John E. Rogers, Port Neches, Tex., assignor to The Lummus Company, New York, N. Y., a corporation of Delaware Application April 28, 1950, Serial No. 158,623

2 Claims. 1

This invention relates to improvements in continuous filters of the rotary drum type.

It is well known that with filters of this type it is common practice to secure the filter cloth by winding the drum with wire. It is necessary that this wire be kept taut and it has been customary to open the filter tank cover in order to get at the wire and make the necessary adjustments.

This is particularly objectionable in the filtration of certain materials particularly where the gases surrounding the filters are of a noxious character or the solvent is corrosive and in any event opening the filter cover is a very cumbersome operation.

The invention is of particular importance in those cyclic filtration operations where the filter is alternately heated up and cooled down with the resulting creeping of the wire. It has been found in some cases for example, that it was necessary to take up the wire every three hours and it is frequent practice to take up the wire to maintain a uniform tension at the end of every shift.

My invention particularly relates to a simplified take-up mechanism which may be attached to the drum along the side wall and be readily adjusted by the simple opening of a handhole.

Further objects and advantages of my invention will appear from the following description of a preferred form of embodiment thereof taken in connection with the attached drawing in which:

Fig. 1 is a partial end view of the filter drum.

Fig. 2 is a partial top plan view taken substantially along the line 2-2 of Fig. 1.

Fig. 3 is an enlarged detail section on the line 3-3 of Fig. 1, the wire being omitted.

The typical filter drum l is a normally cylindrical member rotating about a horizontal axis in a tank, not shown. It passes through the liquid carried in a filter tank and by applying a differential pressure in the well known manner, a filter cake is formed on the filter cloth. The filter cloth 12 is usually held taut against the filter drum by a wire winding l4. Usually this is applied by anchoring one end and feeding the wire in a spiral path across the surface of the drum and anchoring the other end.

Due to the normal operation of the cake removing blade and the tendency of the wire to stretch, it is found that the wire when loose, allows objectionable bulging of the filter cloth and for satisfactory operation a uniform tension should be maintained. The use of springs for this purpose has been suggested but they are Y 2 limited in the amount accomplished.

In accordance with my invention, I attach a bracket it which may be suitably secured to the end wall of the drum l0 as by studs l8. The bracket is provided With a rear bearing plate 19 and a front bearing plate 20 may be detachably held in appropriate position by the same studs I8.

Mounted between the rear bearing. plate I6 and the front bearing plate 20 is a wire receiving spool or hub 22 which may be provided with a suitable Wire end receiving slot 24.

Preferably made integral with the hub 22 but in any event, in driving relation therewith, is the ratchet wheel 26. A pawl 28 is pivotly secured to the bracket l6 at 30 and engages the teeth of the ratchet wheel 26 in a customary manner. The pawl 28 is normally held in detent position by the spring 32.

For appropriate rotation of the ratchet wheel 26 I preferably extend the hub shaft as at 34 and provide it with a polygonal face so that a detachable tool 36 may be used to rotate the ratchet wheel. It will, of course, be appreciated that the hub may be splined and the tool provided with a mating face for driving relation therewith.

The filter hood or cover shown at 40 is provided with a suitable handhole 42 covered by a plate 43 at a position such that the filter drum [0 may be rotated so that the driving connection for the ratchet wheel 26 will be in horizontal alignment therewith. The tool 36 which is a rotary member and may have a crank, not shown, can thus be applied to the ratchet wheel and hub for the desired tightening of the wire [4. If desired, an intermediate spring 45 may be used for continuous tension.

The particular advantage of this construction is its extreme simplicity. There is no turnbuckle or bolts or double nuts or vacuum cylinders to get out of adjustment and by the use of the very simplest form of socket wrench, the desired number of turns may be given to the ratchet wheel for the desired take-up. A simple torque type of wrench could be used for example to give the desired tension to the wire.

The only operation necessary to apply the wrench is to loosen a small handhole which need be but slightly larger in diameter than the end of the wrench. Adjustments can be made quickly and with less expense and with greater satisfaction. Furthermore, there is no actual contact between the mechanic and the equipment of take-up that can be,

3 and it is thus impossible for the mechanic to become burned by the toxic solvents or other filter fluids.

If more than one wire is used, a take-up device will be used for each wire and in such case a plurality of brackets will be mounted at spaced intervals at the end of the drum.

I claim:

1. A wire-tensioning device for a continuous filter of the type including a filter drum mounted for rotation on a horizontal axis in a tank, a filter cloth on the periphery of said drum and an embracing wire wound around said cloth, said tensioning device comprising a substantially fiat unit including a substantially flat bracket removably mounted fiatwise on the outer side of an end wall of the drum in a position inward of the drum periphery to rotate with the drum, a winding hub rotatably borne by said bracket in a position spaced inwardly from the periphery of the drum and having one end of said embracing wire connected thereto for winding same, means guiding the wire from the adjacent peripheral edge of the drum to said hub and. including a pair of pulleys at least one of which is adjacent the periphery of the drum to receive the wire directly therefrom and train it en route to the second pulley and the winding hub, a ratchet wheel fixed to rotate with the hub, a pawl carried by the bracket to engage the ratchet wheel and prevent unwinding rotation of the hub, and a driving member for the hub rotatably borne by the bracket and engageable by a tool for winding rotation of the hub,'the axes of said hub and pulleys being substantially at right angles to said end wall of the drum; a cover for the filter drum having a hand hole so located that said driving member will align therewith at one point in its path around the axis of the filter drum, for insertion of said tool; and a closure for said hand hole.

2. The structure claimed in claim 1 including a spring tensioning device borne by the drum and including a third pulley disposed to receive said wire from said pulley which receives the wire direotly from the drum and train it to said second pulley for passage to said winding hub, and spring means to urge said third pulley away from the said second pulley and impose a constant tension upon the wire, said tensioning device being also positioned at said end wall of the drum and 1ying within the plane of the first device.

JOHN E. ROGERS.

References. Cited in the file of this patent UNITED STATES PATENTS 

